Process of burning gases.



W;A.BUNE.1W. WILSON & c. D. lvlccouRT.

PROCESS 0F BURNING GASES. APPLICATION FILED JuLv|l.19l2. RENEWED SEPT.8, 1916.

Patented Apr. 17, 1917.

vforms based uponand contains subject-matter taken Ere.

WILLIAM anrnun. BONE AND JAMES wrLLraiu WILSON, or LEEDS, man oYErLnoue- LAS' MUCOURT, OF LONDON', ENGLAND,

ASSIGNORS T0 RADIANT HEATING LTMITED,

0F LONDON, ENGLAND, A BRITISH CORPORATION.

Application led July 11, 1912, Serial No. 708,852.

To all whom t may concern:

Be it known that we, WILLIAM ARTHUR BONE, of Leeds, in the. county ofYork, England, JAMES WILLIAM WILSON, of Armley, Leeds, in said county,and CYRIL DOUGLAS MCCOURT, of 4:5v Braxted Park, Streatham Common,London, S. W., England, subjects of the King of Great Britain, have madecertain new and useful Improvements Relating to Processes of BurningGases, of which the following is a specification taken in connectionwith the accompanying drawing, which part of this application, which isfrom our copending United' States application, Serial No. 586,058, filedOctober 8,1910.

This invention relates to processes of utilizing the acceleratinginfluence of the incandescent surface of a highly porous refractorydiaphragm upon the combustion of a suitable explosive mixture of gaseousfuel and air fed in-large volume through the diaphragm toward its heatedouter surface, so that aV large proportion of the thefuel is liberatedas radiant energy fromthe incandescent surface so as tobe available inconnection with manyindustrial gas heating operations. Whenv `anexploslve mixture of coal gas and air, for instance, in their combiningproportions or with air in slight excess thereof is passed at suitablevelocity throughthe pores or interstices of a suitable. crous refractorydiaphragm into its ncan accelerated andsubstantially nameless combustionof the gas takes place within the interstices, pores or .partslof theincandescent diaphragm layer which are .more or less impregnated or in.contact with, the gaseous mixture; and energy thus.. developed in largeamounts by this intensified, completel and efficient combustion isabsorbed -by-the adjacent surface layer of the diaphragm and maintainsit in a state of incandescence, thus securing a very convenient andeflicient source Y*of radiant energy.. This highly accelerated orintensified surface combustion seems to be due tothe emission of chargedcorpuscles or electrons from such incandescent solids, and theconsequent formation of layers of electrified or ionizedr gas in whichthe chemical changes incident to combustion proceed, .withextraordinary'gv rapidity. x Tt has been demonstratedthat-theiincandescent VJmal bustion of an explosive potential energy ofescent surface layer a many fold" PRQCESS OF BURNJING GASES.

@mm Specification of Letters Patent.

Renewed September'il, 1916. Serial No. 119,139.

solid plays anactive, and important part in the combustion of/theexplosive gaseous mixture under these conditions, the particles of theincandescent solid apparently .forming a composite system with centmolecules of the combining that such combustion complex acts ner verygases, so in a mandif'erent from what occurs in norflame combustion. Forexample it has been proved that the presence of water vapor certainlyaccelerates, if it is not essential to, the normal flame combustion ofcarbon monoxid in air or oxygen, whereas the presence of even Aa smallquantity of water vapor such as -will saturate the gases at 18 C.greatly retards the surface commixture of carbon monoxid and oxygen'incontact with heat.- ed ireclay surfaces. Another thing which indicatesthe distinctive and qualitative difference between such surfacecombustion and normal liame combustion is the fact, that in ordinarycombustion methane and other hydrocarbons have much greater afinity foroxygen than either hydrogen or carbon monoxid; while in surfacecombustion these selective' affinities are completely reversed,apparently because of the controlling action of the heated solidparticles'on the manner of combustion.

This invention is adapted for the combustion of a large variety. ofcombustible gaseous material, as for example blast furnace gas, producergas, water gas, which may be carbureted, coke oven gas, coal gas, petrolair gas and similar hydrocarbon gas and other combustible vapors,natural gas and mixtures thereof, all ofgvhich are hereinafter referredto as combustible gases, although the temperature attainablel in anyparticular case will naturally depend upon the calorifcJgintensity '0fthe gaseous material employed. The combustible gas is combined with airor other available supporter of combustion `preferably in substantiallythe combining proportions or with a slight excess or deficiency of air,although the proportions of the constituent gaseous materials may. varyvconsiderably and still secure an explosive vgaseous* mixture, such asmationh possibly under conditions of increased pressure and temperature;

In the illustrative forms of apparatus for f 't `verted convex carryingout this invention shown in the drawings in a somewhat diagrammatic Way,Figure 1 is a verticalcentral section through a form of diaphragmapparatus.

Fig. 2 is asimilar View through a pair of opposed diaphragms. j

Fig. 3 is a similar View showing an indiaphragm in connection with ahood and flue.

Fig-4 shows in section a tubular diaphragm unit.

. Fig. 5 is a diagrammatic view showing a magnified section ofthediaphragm structure; and

. Fig. 6 is a similar view showing diagrammatically one of the channelsin such porous diaphragms.

The porous refractory diaphragm may be given any suitable shape so asto-liave the desired form of incandescent outer surface from which theheat is transmitted. In the illustrative form of diaphragm unit shown inFig. 1 the permeable or porous diaphragm 1 may be in the form of a flatplate of suffici ently refractory material preferably formed ofagglomerated or united particles or grains of substantially uniform sizeso as to form tortuous channels for the passage of the explosive gaseousmixture through the diaphragm. The diaphragm which may be an inch or sothick may be mounted in any desired way, as for instance, by beingsupported in a suitable casing 2 of iron or other suitable materialywhich may be formed with a suitable recess behind the diaphragmcommunicating with the injecting pipe 3 for the' explosive gaseousmixture which for example may be formed by forcing the combustible gasthrough'the inlet pipe 6 in the d esired amounts controlled by the gasvalve 7 while air is similarly supplied under the desired pressurethrough the air inlet pipe L1 to the extent determined by the adjustmentof the air valve 5. In order to keep the edge of the diaphragm cool itis desiiable to minimize the discharge of gas from this part of theouter or discharge surface S of the diaphragm in any suitable way, asfor instance applying a suitable impervious coating 11-to the edge andadjacentinn'er face ofthe diaphragm. A suitable impervious coating forthisV purpose may formed of a mixture of finely groundburned ireclay andsodium silicate which'maybe applied warmed. sufficiently to causesetting of Ithis cement-'like material which forms/ a hard materialsomewhat like Portland cement or limestone. Plaster of Paris or otherimpervious cement-like material may also be used for this imperviouscoating or the de'- sired part of the diaphragm may be rena suitableglaze formed duriiig'its manufacture. 4The diaphragm is preferablymounted within a suitable seat this instance in moistened condition and.their 10 thecasing/ of suchshape. as to substantiallyconform to theedge of the diaphragm which is preferably located so as to be proltectedby the edge or flange 9 of the casing.

Any suitable cement or luting material may be used to hold the diaphragmwithin the casing, a mixture ofinely groundburned fireclay 1 and sodiumsilicate whichm'ay becaused to set by suitable warming, or othersuitable cementitious material, such as plaster `of Paris, asbestospaste, o r whitelead composi- -tions may be used. Such porous refractorymediums when in the form of coherent diaphragms may be arrangedhorizontally, vertically or at anydesired angle andthe hot outer surfacevmay be either the upper or Several diaphragms may be lower surface.arranged in any desired way to supply heat to various parts of an objectand for grilling er toasting purposes, for instance, two diaphragins maybe arranged opposite each other. As indicated in Fig. 2the incandescentdiaphragms 15 and 16 are placed at any suitable distance apart so as toheat both sides of the article placed between them. The diaphragm 15 maybe mounted Within a suitable casing 17 connecting with the injectingpipe 18 and formed with a suitably connected support, if desired. Theopposing diaphragml may be mounted in a similar support 19 having theinjecting pipe 20.

In some cases instead of using phragms many other special forms orcontours suited to special purposes may be used, such, for example, asthe dome-shaped or convex diaphragm shown in Fig. 8. In, this case theporous refractory diaphragm 21 is shown mounted in inverted position, inthe iron or other suitable `casing 22 so as to have the` outer hotsurface of the diaphragm pointed instance in its upper portion or forheating or evaporating liquids or other material placed beneath thediaphragm. As indicated, the

as for instance, ireclay or preferably plain diadownward so as tobesuitable, for for heating a room when 'mounted diaphragm and itsconnected casing may in be convenientlyfsupported by the injecting pipe23-zlfor explosive 'gaseous v mixture, and if desired a suitable hood 24may be mounted in'connecti'on with thediaphragm so as to carry oftheproducts of combustion therefrom in-connection with a suitable flue;such as25. A form of tubular diaphragm '26 is shownin Fig. 4 as`mountedWithin a suitable'casin'g or support 27 of 'iron' orother suitablematerial so that the explosive-:gaseous mixture supplied to thediaphragm through the injecting. pipe 28 maintains the outer, surfaceyoftheporou's diaphragm in incandescent condition. The explosive gaseousmixture may be formed and fed to any such refractory diaphragms whichare sufficiently porous by a suitable injector device in which eitherthe combustible or combustion supporting constituent may be underpressure and be discharged with sufficient velocity to draw in and mixthe other component ofthe explosive mixture and feed the same withsuiiicient pressure through the diaphragm. In Fig. 4 the injector deyicemay as indicated comprise the curved injector throat 29 with which theinjector nozzle 31 co'perates so as to draw in additional gaseousmaterial through the annular passage 32 the size of which may beregulated by adjusting the position of the valve 34 threaded orotherwise adjustably mounted on the nozzle, for instance. The supportingcasing 33 communicating with a suitably valved supply pipe may be usedto connect the injector throat with the pipe 30 communicating with thenozzle so as to allow the entrance of air o-r other gaseous supporter ofcombustion around the nozzle when the combustible gas is' disvchargedtherefrom at a velocity pressure of a few pounds per square inch whichis suiiicient to produce a pressure vbehind the diayphragm of an eighthor a quarter of an inch of water or more. The valve in the gas supplypipe may be us/ed to regulate the amount of gas discharged from theinjecting nozzle and the valve indicated in the air supply pipe mayregulate the amount of air drawn 1n.

These refractory diaphragms of a high and quite uniform degree ofporosity may be manufactured in a numberl of ways, as for instance, by`suitably uniting refractory porous granules of substantially uniformsize so asto give a high degree of porosityv and permeability to thediaphragm which is penetrated by tortuous. gas passages `formed by thenetwork of spaces or interstices between the refractory particles orgrains of which the up. Porous iireclay is a satisfactory ."fna- 'terialfor such diaphragme and may be readily crushed or 'ground in any desiredway into particles or grains of the desired size. The granules formaking any particular class ofdiaphragms are substantially uniformlysized, that 1s, granules passing asieve havin to the linear inch areselecte from objectionable fine material by separating therefrom 'allparticles which will pass a 50 mesh sieve.- Another size of gran-f ulesuseful for such diaphragms for less explosive a 16 mesh sieve andretained by a 32 mesh sieve. Still largersized granules, suchas aresuitable for making diaphragms which may be generally used for burningcoal gas and illuminatin gas are those passing an 8 mesh sieveandretained by a 16 mesh sieve. These porous granules may be united inany ldesired waypreferablyby means which will not destroy or undsirablyimpair the diaphragme are made.

for instance, the:V

30' meshes and freed' gaseous mixtures are those passingmolded while inthis l their porosity of each of the granules. This ma be accomplishedby the use of suitable binding agents, such as incorporating with thegranules a small percentage of feldsparor a mixture of fel'dspar with alittle iiuorspar to the extent of ten per cent. or so of the granules.Such binding material in dry finely powdered form may be incorporatedwith the granules by iirst wettingthemfand then thoroughly stirring themwith! theidry binding material which thereby coats the particles whichmay then he immediately moistened condition. The molded diaphragms arethen burned at a high temperature in a suitable pottery kiln or otherfurnace so that the temperature is carried considerably beyond theIusing point' of the binding material and this causes the bindingmaterial to unite or fuse together the adjacent points of the roughporous material is sufficiently absorbed into the granules to leave themwith rough unglazed surfaces so as not to undesir'ably minimize theirporosity)I rll`he diaphragms areformed by being burned atcalciningtemperatures greatly in excess of workingv temperatures the particlesare firmly and sufficiently rigidly Ih e'ld in position. `'For instance,diaphragms may Abe burned attemperatures of 1300 to .1400 degrecs C. andoperated at teinperatures of 800 or`900 degreesnC. with good results.1t\

`is also desirable to carefully. mold these diaany possibility ocrushing the-particles or undesirably packing them. 1t visalso dessirable to remove the surfaceof the bakedV diaphragms whereA theparticles have become alined as by being in contact with the smooth moldsurface and this may. be donel in any desiredv way as with a rasp beforethey are usedf For some purposes alsomit is .not desirable to use as thedischarge or outer active surface ,of the diaphragms the surface whichhas been in contact witli'the mold`,f"but to use this surface for theinner surface through which the gas enters. 1nl

granules while the vbinding working temperatures so .that at all thisway diaphragms may be formed of en# tremely high and uniform porosity,the degree of porosity, that is, the proportion vof porous cavities andspaces between'the particles 'or granules being as high as 50 per cent.or so in some cases. For some special purposes it is sometimes desirableto form the diaphragms with outer discharge sury faces of'coarserparticles and with bodies or inner layers of finer particles which caninch mesh, which of course be conveniently effected when molding themoist material.

The substantially uniform size of the granu les and the tortuous natureof the gas passages between them are desirable in highly permeablediaphragms suitable for operation under low gas pressures. The size ofthe granules and consequent size of gas passages and permeability ofdiaphragms of this character should be so chosen as to give the properoperation ,with the particular kind of gas with which they are to beused, the size of granules being in all casesc small enough so thattogether with the tortuous character of the gas passages and the greatlyincreased cooling effect due to the impinging action and roughsurfacesof the granules forming these passages, flashback through thediaphragml passages is greatly minimized and practically eliminatedunder operating conditions with the particular explosive gaseousmixtures used. Diaphragms an inch and a quarter or so thick may beformed in this way of porousireclay granules of between one-eighth andone-sixteenth give good results with explosive coal gas and air mixturessupplied under pressures of about one-eighth of an inch of` water, andsuch diaphragms may burn as much as 75 cubic feet or so of coal l v Adiaphragm similarly gas or 400 to 500 cubic feet of explosive coal gasand air mixture per hour for every square foot of diaphragm surface,thus` maintainingthe outer heated surface of the diaphragm at atemperature of about 850D C. or so under freely radiating conditions.formed of granules of substantiallyv sixteen-mesh size will burn asimilar amount of explosive coal gas mixture, but requires somewhathigher pressures, about one-quarter lnch o r so for the same diaphragmthickness. More explosive or inflammable gaseous lmixtures such as thosecomprising water gas containing somewhat larger aconsiderab y finerdiaphragm to eifectlvely suppress backflashing or quick backfiringtherethrough, and for such explosive gaseous mixtures the diaphragm-maybe formed of granules as in'e as about 30 orl 50 mesh' or even ofs'tillfiner granules of between 50 phragms and 100 mesh size in the case ofmore in- .iammable water gas mixtures. l

,-The laction of suchporous refractory diain effecting the acceleratedsurface combustion of explosive mixtures can he; un-

-Aderstood by reference to Fig. 5 which diastructure on a greatlygrammatically illustrates the' diaphlfafll magnified scale. T e

outer granules `or particles 40 of porous'` re.-

the combustion of the explosive gaseous mixroportions of hydrogenrequire conduct-,mg plate or y tures at which fractory material are. theones maintained '1n"\ a highly heated or incandescent' condition by vtures injected against themso as to maintain them in this highly heatedcondition in which they can radiate heat to each other and from the`exposed outer surface of the diaphragm. As may be seen by reference totheAV portion of these granules within the plane ofthis section thegranules not only have rough outer surfaces, but have internal poressuch as 42 communicating in many instances with the outer surfaces toform cavi- 'ties which the gases may readily penetrate. These particlescles 4:1 are firmly united, but have relatively large cavities orinterstices, so that the entire diaphragm is formed with a net work orconcatenation of' these communicating spaces or channels. Fig. 6illustrates dia'- grammatically the character of one of these tortuousgas passages or channels ,44 through a diaphragm cof this character, thesection being taken along the' irregular line following the greatestcross-section of thisparticular channel through the porous particles.These same factors promote the surface com-, bustion action occurring inthe hot outer layer of the, diaphragm several granules thick. Theexplosive gases are here brought into impingement with the roughincandescent surfaces of the granules so that penetration and contactwith the gas is greatly proand the similar inner partimoted and highlyaccelerated combustion takes place much more effectively thanv drilledwith A that it can undesirably heat by conduction the rearward layers ofthe diaphragm and thus cause the zone of surface combustion of theexplosive gases to slowly andprogressively move back away from the outersurface. This back heating action occurs when, for example, two coal gasdiaphragme are arranged with their incandescent surfaces close together,or when a refractory nonthe like is moved against hot diaphragm, and mayalso take place when excessive amounts of the gaseous mixtures are.being "burned in the diaphragm so that the heat developed exceeds thatwhich can be properly dissipated from the radiating diaphragm surface atthe relatively moderate incandescent temperait seems preferable tooperate these diaphragms. Whensuch back heating takes place the outerdiaphragm surface actually frequently cools of after the combustion zoneor incandescent layer has moved backward into the diaphragm, and

or close to a instead of a substantially uniform 1ncandes 130 ithe'explosive gases in the conditions are restored.

ated by surface combustion,

lse

cent diaphragm surface cent surface darker spots appear and in manyinstances the outer surface cools below a bright heat when thecombustion layer has retreated some distance. l/Vhen this slowretrogression or ypenetration of the hot combustion zone through thediaphragm occurs diaphragm chamber may become ignited, and it is ofcourse desirable to quickly correct this undesirable action as byshutting off the gas supply and cooling the diaphragm or by considerablyincreasing the proportion of air mixed with the combustible gas suppliedso that normal Then the relatively from the incandesshould be insured soas to radiate the heat as fast as it is generand prevent the progressiveaccumulation of heat and rise of temperature in the incandescent surfacelayer which undesirably heats the adjacent material and initiates suchbackheating. In normal operation. of such refractory diafreer radiationof heat Aphragm the explosive gaseous mixture continues to burn withaccelerated surface combustion in the incandescent surface layer andthis combustion may be definitely localized and maintained at thedesired intensity by regulating the supply of explosive gases and theamount of heat radiation as by increasing or diminishing the freedom ofraidiation, so as' to insure equilibrium and instance, in the coalcounteract any unbalancing tendencies in the heating system. This backheating action is distinct from the ordinary backiashing or quickbackfiring of explosive gaseous mixtures in tubes, such backiiringaction being suppressed or eliminated in diaphragm operation by thegreatly increased cooling effect on the asesof the small granules andthe relative y large surface ofthe tortuous gas passages therethrough.AFor gas diaphragms `referred to having granules of between one-eighthhood of 30 to and one-sixteenth inch mesh, the passages are ofappreciable size and the porosity is so l great` that thee, total areaof theI passages through the diaphragm is in the neighborsquare inchesfor each square foot of diaphragm surface. lBut nevertheless, nobackiiring occurs with a properly made diaphragm of this character, and

the importance of the tortuous roughened character of the gasbackflashing can be fact that only a square foot passages in preventingappreciated from the as much gas will pass through diaphragm of thischaracter as I will' issue from an orice ornozzle about one-quarter orone-half inch 1n diameter under equal pressures. n gradually shuttingoff the gas supply to diaphragmslof this character the speed of theexplosive mixture passing through the tortuous channels of the diaphragmis gradually reduced to zero, of the diaphragm structure is such as toprevent backflashing of the explosive gases in contact with theincandescent outer face of the diaphragm even under these conditions;and such diaphragms may be regularly operated when the speed of theexplosive gases through the diaphragms is much less than the normalspeed of backliashing of the mixtures.

It is of course understood that many other refractory substances suchbauxite, ganister, preferably those having a suficiently porouscharacter may be used to form the granules which may be united in manyWays to form porous diaphragms of this character. pVarious..tirebrick'compositions havel proved highly desirable, especially the more porousrefractory materials of this character.

Having described these inventions in connection with a number ofillustratiye embodiments, arrangements, proportions, materials,pressures, conditions, processes and orders of steps, to the details ofwhich disclosure the inventions are not, of co/urse, to be limited, whatis claimed as new and what' is desired to be secured by Letters latentis set forth in the appended claims.

1. The process of burning explosive gaseous mixtures which consists incausing the mixture to flow with a velocity less than the normal speedof back-firing of the mixture through tortuous passages of a porousrefractory diaphragm to a highly heated surlface layer thereof, eectingcombustion of the mixturewithin'said highly heated surface layer of thediaphragm, and preventing backlashing by the cooling action of portionsof the diaphragm through which the mixture iiows on its way uto thecombustion zone, whereby the combustion is localized within the surfacelayer of the diaphram and such surface layer is maintained in a. stateof incandescence.

2. The process of burning explosive gaseous mixtures which consists incausing the mixture to flow with a velocity less than the normal speedof back-ring through tortuous passages of a porous refractory diaphragmto a highly vheated surface layer thereof, effecting combustion of themixture with'n said highly heated surface layer of the diaphragm,preventing bacldiashing by the cooling action of portions of the.diaphragm through which the mixture flows on its way to the combustionzone, and permitting heat to radiate freely from said highly heatedsurface layerv of thel diaphragm, whereby the combustion is localizedwithin the surface layer of the diaphragm and such surface layer ismaintained in a state of incandescence.

' 3. rihe process of burning explosive gaseous mixtures which Aconsistsin causing the mixture to flow with a velocity less than the asmagnesia, f

normal speed of back-firing of the mixture `the diaphragm to impmgeonthe through tortuous irregular sectioned passages of a porousrefractory diaphragm to a highly heated surface layer thereof, effectingcombustion of the mixture within said highly heated surface layer of thediaphragm, and preventing backilashing by causing the mixture as itadvances through walls of the tortuous4 passages of the diaphragm,wherebythe combustion is localized within the surface layer of thediaphragm and such surface layer is maintained in a state ofincandescence.

4. The process of burning gaseous fuel which consists in combining thegaseous fuel with a gaseous supporter of combustion in proportions toform an explosive gaseous mixture, causing the'l mixture to flow with avelocity less than' the normal speed of back-firing of the mixturethrough a porous refractory diaphragm to a highly heated surface layerthereof, effecting combustion of the mixture within said highly heatedsurface layer of the diaphragm, and preventing backlashing by thecooling action of portions of the diaphragm through which the mixtureflows on its way to the combustion zone, whereby the combustion islocalized within the surface layer phragm and such surface layer ismaintained in a state of incandescence.

5. The process of ous mixtures which consists in causing the mixture toflow with a velocity less than the normal speed of back-firing through aporous refractory diaphragm to a highly heated surface layer thereof,effecting accelerated surface combustion of the mixture within saidhighly heated surface layer of the diaphragm, and preventingbackfiashing by the cooling action of portions of the diaphragm throughwhich the mixture flows on its way to the combustion zone, whereby thecombustion is localized'within the surface layer of the diaphragm andsuch surface layer is maintained in a state of incandescence.

WILLIAM ARTHUR BONE. `JAMES WILLIAM WILSON.

CYRIL DOUGLAS MCCOURT. Witnesses:

M. G. SPALDING, CHARLES E. TAYLOR.

of the dia-- burning explosive gase

